bwn update

[Imre Vadasz]

Hi,
Just FYI, since nobody at FreeBSD has picked this stuff up yet (and I don't
have the time or energy to work on FreeBSD as well). In the DragonFly port
of bwn(4), we have fixed a few typos and added a few bugfixes (which end up
improving bwn(4)'s performance and stability a lot on my BCM4312 chipset
('BCM4311 802.11a/b/g' in pciconf -lv)):

A fix for RF switch state polling:
http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/202e28d1f65e9f35df6032400df3242a3bafb483

Remove a superfluous ieee80211_start_all call:
http://gitweb.dragonflybsd.org/dragonfly.git/commit/9ce8b3ee47294f82be9c626470deefb943eb2cb1

A fix for a DMA issue on some chipsets, and a fix for a performance
problem on my BCM4312 (and maybe other chipsets):
http://gitweb.dragonflybsd.org/dragonfly.git/commit/b7a8b6abd2cfa6cd927aefa770aff3030ffce28c